Power utilities are concerned with the generation, transmission and distribution of electrical power. The physical assets or devices used in power utilities have specific properties associated with them. Examples of such physical assets include stations, lines, transformers or breakers. The properties include, for instance, a nominal primary voltage or a momentary tap position of a transformer. For maintaining, operating, controlling and/or monitoring these physical assets, various local applications and corresponding Information Technology (IT) systems are employed. The term “local” in the context of the present disclosure does not relate to a geographical property, but refers to the fact that these applications are concerned only with certain aspects of the physical assets. Examples of such local applications include a Computerized Maintenance Management System (CMMS), a Supervisory Control And Data Acquisition (SCADA), a Geographic Information System (GIS), an Enterprise Resource Planning System (ERP) and the like. In the context of power utilities, CMMS comprises e.g. active and archived work reports as well as new work orders, and allows to dispatch maintenance crews. SCADA comprises an electrical view on the assets of the electrical network in order to operate breakers and switches, and monitor voltages, currents or capacity limits, whereas GIS is used to optimize maintenance operations through the spatial view on the assets.
The physical assets are modeled in the various local applications as objects carrying specific attributes with them. The physical assets are referred to in a number of different ways due to the fact that each local application is responsible for different aspects of managing the physical asset. In addition, each of the corresponding IT systems allows modification of the underlying data sets, both for an initial setup and continuous updates, i.e. attributes can be changed and objects can be inserted or deleted at runtime, either automatically or initiated through operators and utility personnel. Such modifications on the system side reflect the frequent modifications of e.g. the electrical network of a power utility through commissioning or disposal of physical assets, which subsequently imply changes in one or more of the local application's data sets. The foregoing may result in inconsistent data, e.g. an attribute having different values in the control and maintenance system, or a new object being inserted in the planning system but still missing in the maintenance system. This inconsistency is a consequence of insufficient coordination and automation of work processes.
As the physical assets concerned by the abovementioned modifications share a certain extent of information with several local applications or corresponding IT systems, any inconsistency should be resolved and the data concerned should be updated across the IT systems in order to ensure information consistency among the local applications. However, on the IT side, navigation between, synchronization of and consolidated access to information stored in the various systems in operation is complex and maintenance efforts are generally huge.
All IT systems work on either real-time or standard database products. A synchronization or replication of all these databases triggered by the faintest change in one single attribute obviously is computationally expensive. In addition, synchronizing real-time database applications such as SCADA and standard database applications may not be feasible at all. Furthermore, a direct synchronization on the database level is not suited for utility applications, since applications usually perform a multitude of security and sanity checks in order to ensure that modifications on objects are possible and allowed with the current configuration. Therefore, the only suitable method for accessing those local applications' data sets is by accessing the information through the Application Program Interface (API) provided by the corresponding IT system.
In addition, a hardware or software component of one of the IT systems might fail during operation. For instance, in case of a communication failure to a local application, changes being made inside this local application go by unnoticed by the other local applications. In order to restore consistency, components are deployed in a redundant way, such that failure of hardware or software components can be overcome. However, systematic errors cannot be resolved through this approach. On the other hand, an alternative approach to regularly poll all local applications for changes puts a heavy load on all communication channels and is not feasible in large utilities with millions of assets.